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Broken controller due to moisture

Started by taskrov, July 25, 2021, 11:57:57 AM

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My RadRunner that I purchased in Nov '19 stopped working. It keeps blowing the 40A fuse located in the battery. I checked everything per Help articles on RadPower site but no help. Finally, I decided to take a look at the controller itself. I opened the box and found a lot of junk from moisture inside. I never ride the bike when it is wet, but I have run through small puddles if I could not avoid it. The controller is not water tight at all. There are no seals and the cover does not fit tightly so no wonder water got there. Anyway, I also found one of leads from the (large) capacitor corroded away. That is bad design! I wrote to RadPower Support to see what they have to say.
I attached a pic of the controller and the missing wire is circled.


Quote from: taskrov on July 25, 2021, 11:57:57 AM...I never ride the bike when it is wet, but I have run through small puddles if I could not avoid it. The controller is not water tight at all...

Amen (except for the couple of times I got caught out in the rain, but hid under bridges before getting soaked, and maybe started out again on wet  pavement too soon, before it completely dried out).

Anyway, after examining the seals on my 2020 RadMini4 controller, I came to the same conclusion you did, and I was always cleaning mud and other gunk off the outside of it. So I made a shield out of clear 6 mil polyester/Mylar/BoPET secured by just 2 small 14 lb tie wraps that I planned on leaving in place just through the spring mud/puddle season. We've had a relatively wet last few months so it's still there, and just may be a (semi)permanent thing. It wraps around underneath the bottom bracket to also protect the rats nest bundle of wires there from road splash up and dust.

Time will tell if the lack of airflow over the controller causes overheating on long steep Assist Level 4 or 5 climbs, but so far no problems.


Great idea! When I get a replacement controller I will probably open the case and apply some sealant all around to make it waterproof, and also make some kind of enclosure to prevent water splashing on the controller.  I am thinking this particular controller was not assembled properly and that is why this happened to me so soon.

I have seen some controllers for the RadMini that is supposed to be plug-and-play for the Runner. Maybe those are better constructed, unfortunately the website lists them as Sold Out.


Interesting Im suspecting the same problem. My almost new Rad 5 turns off right after I turn it on and I hear a faint click from inside the controller.  I've reconnected all the connectors.  RadPower is sending a replacement.  I'll examine the old one. I suspect something in there is shorted.  I'll put a plastic bag around the new one. 

I just removed my old controller and it is air tight, filled with foam to keep moisture out.  Just saying.   Moisture didn't get it.  I'll install replacement when it arrives.

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